Surface Hardening of Parts Arc

2016 ◽  
Vol 843 ◽  
pp. 225-230 ◽  
Author(s):  
L.I. Korolkova ◽  
N.M. Mashrabov
Keyword(s):  
Surface Hardening ◽  
Electric Arc ◽  
Temperature Fields ◽  
Critical Rate ◽  
Inert Electrode ◽  
Cylindrical Parts ◽  
Machine Elements ◽  
Rate Of Cooling ◽  
Explicit And Implicit Schemes ◽  
First Time

The paper presents the results of studies aimed at justifying and developing the ways and means of cylindrical parts made of hardenable alloys surface hardening by heating of the electric arc between the inert electrode and the element. The shapes of electrode sharpening and the position of the electrode relative to the element are substantiated. The sequence of surface hardening operations is revealed and the critical rate of cooling is determined and its value is proved with numerical experiments. It was necessary to develop a program for calculating temperature fields in details, with a difference-differential scheme obtained from a combination of explicit and implicit schemes being developed for the first time. A number of investigations were conducted to determine the mechanical properties, the residual stresses, the fatigue resistance, the hardness and the microstructure of hardened layers. As a result, the surface hardening technology is recommended for reconditioning and manufacturing cylindrical machine elements.

scholarly journals Temperature Dependence of Thermophysical Properties of Full-Scale Corium of Fast Energy Reactor

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Mazhyn K. Skakov ◽  
Nurzhan Ye. Mukhamedov ◽  
Alexander D. Vurim ◽  
Ilya I. Deryavko
Keyword(s):  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Fast Reactor ◽  
Thermophysical Properties ◽  
Heat Conductivity ◽  
Nuclear Reactor ◽  
Reactor Vessel ◽  
Full Scale ◽  
Temperature Fields ◽  
First Time

For the first time the paper determines thermophysical properties (specific heat capacity, thermal diffusivity, and heat conductivity) of the full-scale corium of the fast energy nuclear reactor within the temperature range from ~30°С to ~400°С. Obtained data are to be used in temperature fields calculations during modeling the processes of corium melt retention inside of the fast reactor vessel.

Possibilities of Use of the Thermographic Measurement as a Tool for Detecting Defects and Improving the Production Process

2015 ◽  
Vol 1127 ◽  
pp. 23-29
Author(s):  
Eva Rykalová ◽  
Zdeněk Peřina ◽  
Radek Fabian ◽  
Petr Jonšta
Keyword(s):  
Friction And Wear ◽  
Refractory Lining ◽  
Steel Ingot ◽  
Electric Arc ◽  
The State ◽  
Temperature Fields ◽  
Arc Furnace ◽  
Casting And Solidification ◽  
Steel Ingots ◽  
Thermographic Measurement

Infrared radiometric long-waved systems are widely used in various industries as well as in research and development. This long-waved system is the perfect tool for quick diagnosis of the state of the equipment, easy defect detection, which is reflected by higher temperatures due to increased friction and wear. Infrared radiometric long-waved systems are used especially in civil engineering, electrical engineering, metallurgy and many other industries. They are also used to optimize and improve of the production processes. The series of measurements using the infrared radiometric long-waved system in steel plant were carried out due to prepared research project. Images of temperature fields of ladles with liquid steel, cooled exhaust knee of electric arc furnace and ingot mould were obtained during solidification of steel ingot. Information about the state of wear of the refractory lining of the ladle, exhaust knee can be gained from obtained images. The obtained results can be used for more accurate numerical simulations of the process of casting and solidification of steel ingots.

Influence of the magnetic permeability on modeling of induction surface hardening

2017 ◽  
Vol 36 (2) ◽  
pp. 555-564 ◽  
Author(s):  
Jerzy Barglik ◽  
Albert Smalcerz
Keyword(s):  
Magnetic Permeability ◽  
Surface Hardening ◽  
Calculation Model ◽  
Temperature Fields ◽  
Hardness Distribution ◽  
Current Frequency ◽  
Content Type ◽  
Magnetic Strength ◽  
Gear Wheels ◽  
Induction Surface Hardening

Purpose Modeling of induction surface hardening strongly depends on accuracy of material properties data and their temperature characteristics. However, it is especially complicated in case of the magnetic permeability dependent not only on temperature but also on the magnetic strength. This paper aims to estimate the influence of the magnetic permeability on modeling of coupled physical fields describing the process. Investigations are provided for the gear wheels made of the steel C45E. Design/methodology/approach Computation of coupled electromagnetic temperature and hardness fields is based on FEM methods. The Flux 3D software is applied for the numerical simulation of coupled electromagnetic and temperature fields. The QT Steel software is applied for a determination of the hardness and microstructure distributions. Findings Obtained results may be used as a kind of background for the design of induction surface hardening systems. Research limitations/implications The presented calculation model provided quite a good accuracy of hardness distribution validated by the experiments. Next work in the field should be aimed at taking into account a dependence of the magnetic permeability on the field current frequency. Originality/value Mathematical model of induction surface hardening with taking into account time dependence on the magnetic permeability on temperature and magnetic strength is elaborated. Experimental validation of hardness distribution is provided. A quite reasonable convergence between simulations and measurements was achieved.

Mathematic Model and Method for Solving the Heat-Exchange Problem in Electron-Beam Welding of Arbitrary Areas

2019 ◽  
Vol 291 ◽  
pp. 173-182
Author(s):  
Mykhailo Berdnyk
Keyword(s):  
Electron Beam ◽  
Electron Beam Welding ◽  
Integral Transformation ◽  
Mathematic Model ◽  
Convergent Series ◽  
Dirichlet Boundary Conditions ◽  
Temperature Fields ◽  
The Finite Element Method ◽  
Finite Space ◽  
First Time

For the first time in this article, a mathematical model has been developed for calculating the temperature fields in arbitrary areas in electron-beam welding; this model was created in the form of a boundary value problem of mathematical physics for a parabolic equation of heat conductivity with Dirichlet boundary conditions. A new integral transformation was constructed for a two-dimensional finite space, with the use of which, as well as the finite element method and Galerkin's method, a temperature field has been determined in the form of a convergent series.

Effects of a Transverse Magnetic Field on a Constricted Electric Arc

1975 ◽  
Vol 97 (2) ◽  
pp. 267-273 ◽  
Author(s):  
F. W. Ahrens ◽  
H. N. Powell
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic ◽  
Electric Arc ◽  
Temperature Fields ◽  
Viscous Force ◽  
Tube Radius ◽  
Current Tube ◽  
Two Dimensional Flow ◽  
Current Characteristics ◽  
A Current

The interaction of a constricted electric arc (argon at 1 atm) with an applied perpendicular magnetic field has been investigated analytically. The resulting (two-dimensional) flow and temperature fields, conductive and radiative wall heat transfer, and voltage-current characteristics of the arc are predicted. Three characteristic parameters are isolated: (I/a = current/tube radius), (Re = Lorentz and viscous force parameter), (RT = radiation parameter). When radiation is negligible, the first two are sufficient to scale the effects of any combination of current, tube radius, and applied magnetic field strength. A twin vortex flow pattern is predicted, with the displacement of the vortex “eyes” greatest for high applied magnetic fields and low currents. Comparisons with experimental results from the literature are good to satisfactory.

scholarly journals Reservoir-scale transdimensional fracture network inversion

2019 ◽  
Vol 49 ◽  
pp. 207-214
Author(s):  
Márk Somogyvári ◽  
Michael Kühn ◽  
Sebastian Reich
Keyword(s):  
Thermal Conditions ◽  
Thermal Anomaly ◽  
Fracture Network ◽  
Reservoir Rock ◽  
Monte Carlo Algorithm ◽  
Temperature Fields ◽  
Inversion Method ◽  
Reconstructed Temperature ◽  
Borehole Temperature ◽  
First Time

Abstract. The Waiwera aquifer hosts a structurally complex geothermal groundwater system, where a localized thermal anomaly feeds the thermal reservoir. The temperature anomaly is formed by the mixing of waters from three different sources: fresh cold groundwater, cold seawater and warm geothermal water. The stratified reservoir rock has been tilted, folded, faulted, and fractured by tectonic movement, providing the pathways for the groundwater. Characterization of such systems is challenging, due to the resulting complex hydraulic and thermal conditions which cannot be represented by a continuous porous matrix. By using discrete fracture network models (DFNs) the discrete aquifer features can be modelled, and the main geological structures can be identified. A major limitation of this modelling approach is that the results are strongly dependent on the parametrization of the chosen initial solution. Classic inversion techniques require to define the number of fractures before any interpretation is done. In this research we apply the transdimensional DFN inversion methodology that overcome this limitation by keeping fracture numbers flexible and gives a good estimation on fracture locations. This stochastic inversion method uses the reversible-jump Markov chain Monte Carlo algorithm and was originally developed for tomographic experiments. In contrast to such applications, this study is limited to the use of steady-state borehole temperature profiles – with significantly less data. This is mitigated by using a strongly simplified DFN model of the reservoir, constructed according to available geological information. We present a synthetic example to prove the viability of the concept, then use the algorithm on field observations for the first time. The fit of the reconstructed temperature fields cannot compete yet with complex three-dimensional continuum models, but indicate areas of the aquifer where fracturing plays a big role. This could not be resolved before with continuum modelling. It is for the first time that the transdimensional DFN inversion was used on field data and on borehole temperature logs as input.

Surface hardening of steel components with a constricted electric arc

2003 ◽  
Vol 17 (7) ◽  
pp. 570-572
Author(s):  
A E Mikheev ◽  
S S Ivasev ◽  
A V Girn ◽  
N A Terekhin ◽  
V V Statsura
Keyword(s):  
Surface Hardening ◽  
Electric Arc

On-Line Monitoring of the Electric Arc-Spraying Process Based on Acoustic Signatures

1995 ◽  
Vol 209 (5) ◽  
pp. 369-379
Author(s):  
R Kovacevic ◽  
R Mohan ◽  
M Murugesan ◽  
A F Seybert
Keyword(s):  
Stochastic Modelling ◽  
Electric Arc ◽  
Arc Spraying ◽  
Experimental Proof ◽  
Loop Control ◽  
Acoustic Signatures ◽  
On Line ◽  
Taguchi’S Design Of Experiments ◽  
First Time ◽  
Spraying Process

Electric arc spraying (or metal arc spraying) is a process that deposits metal particles on suitable substrates using two consumable wire electrodes. The high-temperature arc formed between these electrodes in an atomizing jet of air produces small molten particles which are used to coat the substrate. The contribution of the process parameters and their interactions on the coating thickness is analysed using Taguchi's design of experiments. The time and frequency domain sound signals generated during the process are utilized to characterize the spraying phenomenon. Stochastic modelling of acoustic signals forms the basis for a closed-loop control mechanism of the arc-spraying process proposed for the first time. Experimental proof of the Gaussian nature of the deposition profile is provided and a mathematical approach has been suggested to obtain a uniform deposit thickness in a single pass.

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